A number of exercise machines such as treadmills and stationary bicycles are particularly well suited for cardiovascular conditioning. Accordingly, it is often desirable to equip such exercise machines with a device capable of monitoring the pulse rate of a user as he or she exercises and displaying the monitored pulse rate in "real-time." Such real-time displays of pulse rate provides the user with invaluable feedback as to the quality of the workout. For example, users often seek to maintain an elevated pulse rate for a predetermined time period and need a pulse rate monitor in order to determine that the target elevated pulse rate has been reached.
As a result, for a number of years, many exercise machines have been equipped with pulse rate monitors. To measure the pulse rate of a user of an exercise machine, a pulse rate monitor must include some type of sensor which comes into physical contact with the user. Certain early designs of pulse rate monitors included a sensor (or sensors) clipped onto the finger or ear. Other designs located the sensor on a strap which wrapped around the waist. An electrical cable would then extend from the sensor in contact with the body to the circuit which calculates pulse rate from the data collected by the sensor. However, as sensors which attached directly to the body were often viewed as being uncomfortable to wear and/or annoying to use, the incorporation of pulse rate monitoring systems into exercise machines remained limited.
The aforementioned deficiency has been overcome in recent years by physically incorporating the sensors into the support structure of the exercise machines. For example, U.S. Pat. No. 5,337,753 to Lechtman discloses a heart rate monitor in which the electrodes which must be placed in contact with the body are disposed on the outer surface of an elongate hollow cylindrical member while the circuitry which calculates the heart rate is housed within the member. Lechtman further discloses that the cylindrical member may be attached to the handlebar of a stationary bicycle where it may be readily gripped by the user. Similarly, some treadmills are designed such that electrodes are formed at selected locations along side bars of the exercise machine while pulse monitoring circuitry is incorporated into a control pad used to operate the machine. While such pulse rate monitoring systems have proven to be quite popular, there remain a number of deficiencies associated therewith. First, the electrodes are fixed in a position deemed by the manufacturer as the preferred position for grasping the treadmill while exercising. However, individual preferences often vary. For example, while the manufacturer may have located the electrodes at the general center of each side bar, some users may prefer to grasp the side bars much closer to the front of the machine while others prefer to grasp a front bar of the exercise machine with both hands. If the electrodes are located anywhere besides the precise location where a user prefers to grasp the exercise machine, the pulse monitoring system may be deemed to be an annoyance to use. This is a particular concern in private clubs, gyms and other exercise facilities which strive to purchase machines which will appeal to the largest possible portion of its membership. Another problem is that such pulse monitoring systems can only be readily installed during the manufacture of the exercise machine. As exercise machines which incorporated such pulse rate monitoring systems did not appear in significant numbers until the last few years, many exercise machines purchased a number of years ago, but which are still in use, lack such pulse rate monitoring systems. Upgrading the exercise machines to a newer model which includes a pulse rate monitoring system is rarely an option, particularly in the home market where the relatively high cost (often exceeding $2,000) of high quality exercise machines presents a considerable bar to the replacement of the machine simply because it lacks a pulse rate monitor.
There are a number of pulse rate monitoring systems suitable for use as "after-market" retrofits. For example, U.S. Pat. No. 4,319,581 to Cutter discloses a heart pulse monitoring apparatus which may be slid over the handlebars of an stationary bicycle. However, the device disclosed in Cutter is not suitable for use in conjunction with many exercise machines such as those characterized by side bars for which the ends thereof are integrally formed with or otherwise attached to the remainder of the frame of the exercise machine. Recently, an after-market pulse rate monitoring system suitable for use with certain models of the Trimline treadmills manufactured by Hebb Industries, Inc. of Tyler, Tex. was introduced. The pulse rate monitoring system is comprised of an elongated, generally cylindrical bar which extends about two feet in length. Formed roughly two-thirds of the way between the general center and the respective ends are the bar are first and second electrodes designed to be grasped by a user. Each of the electrodes are electrically connected to a pulse rate detection and display device snap-mounted onto the bar at the general center thereof by conductors which extend along an interior passageway of the bar. When the pulse rate monitoring system is turned on and the operator grasps each of the electrodes with a respective hand, the user's pulse rate will appear on the display located at the general center of the bar.
Fixedly attached to the respective ends of the bar are mounting clamps sized to receive a generally tubular side bar of a Trimline treadmill. To mount the pulse rate monitoring system to a Trimline treadmill, a removable portion of each clamp is detached. The clamps are placed over the side bar and the removable portion resecured to the remainder of the clamp to mount the pulse rate monitoring system to the treadmill. On one side, the removable portion snappingly engages the clamp and, on the other, the removable portion is screw-mounted to the clamp. While this pulse rate monitoring system is suitable for mounting to an existing treadmill having side bars ill-suited for slidingly receiving a pulse rate monitoring system onto the ends thereof, the foregoing pulse rate monitoring system is equally limited in its range of applications. Specifically, the bar has a specified length and the clamps are fixed in location to the remainder of the bar. As a result, the pulse rate monitoring system may only be mounted onto treadmills or other exercise machines which have a pair of side bars separated by approximately 27 inches. However, side bars for treadmills are often separated by as much as 34 inches. For such treadmills, the bar could not be mounted to the machine. Indeed, the pulse monitoring system cannot be used with many of the exercise machines manufactured by Trimline itself. Thus, the pulse monitoring system is not particularly well-suited to be moved between machines. Finally, like all other pulse rate monitoring systems, the Trimline system requires that the user grasp the electrodes at set locations which may or may not be the locations where the user is most comfortable with.
Therefore, what is needed is a removably mountable pulse rate monitoring system suitable for use with a wide variety of exercise machines and which allows the electrodes thereof to be placed at a location preferred by the user and not mandated by the design of the device. It is, therefore, the object of this invention to provide such a device.